Biomedical subjects

Shawn D Gale

Publications and source records attributed to Shawn D Gale.

7 recordsLinked to original sources

PubMed2006

Brain atrophy and cognitive impairment in survivors of Acute Respiratory Distress Syndrome.

PRIMARY OBJECTIVES: Acute Respiratory Distress Syndrome (ARDS) is characterized by severe acute lung injury, hypoxemia and is associated with neurological and cognitive impairments. This study assessed quantitative brain and ventricular volumes in survivors of ARDS with brain computed tomography (CT) scans compared to normal controls. It also compared the medical and cognitive outcome data of patients with ARDS with and without CT scans. RESEARCH DESIGN: Observational cohort study. METHODS: Sixty-six consecutive acute respiratory distress patients, of which 15 patients with ARDS underwent brain CT and 51 patients had no brain imaging. Brain CT scans from 15 survivors of ARDS were compared to age- and sex-matched normal controls. Clinical radiological findings and ventricular volumes, brain volume and generalized brain atrophy. RESULTS: The patients with ARDS and brain imaging had cognitive impairments, significant brain atrophy, ventricular enlargement and 53% had atrophy or lesions by radiological report. CONCLUSIONS: Clinicians need to be aware that ARDS can cause significant long-term brain-related morbidity manifest by brain atrophy, lesions and neurocognitive impairments.

Acute Disease↗

PubMed2004

Effects of hypoxia on the brain: neuroimaging and neuropsychological findings following carbon monoxide poisoning and obstructive sleep apnea.

Hypoxia damages multiple organ systems especially those with high oxygen utilization such as the central nervous system. The purpose of this study was to compare the neuropathological and neuropsychological effects of hypoxia in patients with either carbon monoxide poisoning or obstructive sleep apnea. Neuroimaging revealed evidence of hippocampal atrophy in both groups although a linear relationship between hippocampal volume and memory performance was found only for selected tests and only in the sleep apnea group. There were significant correlations between hippocampal volume and performance on measures related to nonverbal/information processing. Generalized brain atrophy, as measured by the ventricle-to-brain ratio, was more common in the carbon monoxide poisoning group compared to the obstructive sleep apnea group. Performance on tests of executive function improved following treatment with nasal continuous positive airway pressure treatment in the obstructive sleep apnea group but there was no associated improvement in general intellectual function. We found that hypoxia due to obstructive sleep apnea and CO poisoning resulted in neuropathological changes and neuropsychological impairments. The observed group differences provide insight into the relationship between etiology of injury, neuropathological changes, and clinical presentation.

Adult↗

PubMed2004

Neuroimaging correlates of the Halstead Finger Tapping Test several years post-traumatic brain injury.

Eight healthy volunteers and seven post-acute patients with a history of severe traumatic brain injury (TBI) performed the Halstead Finger Tapping Test while undergoing functional magnetic resonance imaging (fMRI). Patients with TBI were on average 18.5 years post-trauma and at that time had normal or near normal tapping speeds. The fMRI analysis revealed greater bilateral frontal activation in healthy controls while tapping only in the right hand compared to patients with TBI. The maximum area of activation differences involved the supplementary motor area. Voxel-based morphometry (VBM) failed to reveal signs of atrophy to explain these findings. Different patterns of brain activation in patients with TBI compared to healthy controls may be seen even when the level of behavioural performance of patients is generally within normal limits.

Adult↗

PubMed2003

F-wave acquisition using low-current stimulation.

The purpose of this study was to assess the feasibility of utilizing low-current stimulation for F-wave generation, thereby avoiding the discomfort of repetitive supramaximal stimulation. We employed the same technique as is used for generating F waves in the conventional way, except for using a stimulating current that was just strong enough to evoke a motor response on the oscilloscope. This usually required a stimulus of about 10-15 mA at 0.2-ms duration. Both median nerves of 30 subjects were evaluated with this technique and with F waves generated by the conventional technique in the same subjects. Amplitudes were larger when using supramaximal current stimulation. However, there was no statistical difference between F-wave latencies, chronodispersion, and persistence (penetrance) elicited with maximal and low-current stimulation. This procedure should represent a significant improvement for patient comfort during electrodiagnostic procedures involving F-wave studies.

Adult↗

PubMed2003

Relationship of initial hematocrit level to discharge destination and resource utilization after ischemic stroke: a pilot study.

OBJECTIVE: To examine the association between initial hematocrit level at the time of ischemic stroke, discharge destination, and resource utilization. DESIGN: Case series. SETTING: University hospital. PARTICIPANTS: A total of 1012 consecutive patients with ischemic stroke admitted to a university health system between August 3, 1995, and June 24, 1999. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Length of stay, hospital cost, and discharge disposition. RESULTS: Of 1012 patients presenting with ischemic stroke, 58% were discharged home, 10% were discharged home with home care services, 15% were discharged to a rehabilitation hospital, 11% were discharged to a skilled or intermediate care facility, and 6% died. After adjusting for age, sex, race, and comorbidities, a significant association (P=.009) existed between discharge outcome and initial hematocrit level. The probability of achieving an equivalent or less favorable outcome increased at both high and low hematocrit levels, with a minimum probability at a hematocrit level of approximately 45%. CONCLUSIONS: An association exists between hematocrit level at the time of ischemic stroke and discharge outcome. Midrange hematocrit levels appear to be associated with discharge to home rather than to an inpatient rehabilitation unit or to a nursing facility. Further study is indicated to examine the relationship among hematocrit level, stroke severity, and outcome.

Aged↗

PubMed2002

Mixed median nerve forearm conduction velocity in the presence of focal compression neuropathy at the wrist versus peripheral neuropathy.

OBJECTIVES: To establish normal values for the conduction velocity of the mixed median nerve in the forearm, and to determine the use of mixed median nerve conduction velocity (NCV) studies across the forearm in the differential diagnosis of carpal tunnel syndrome (CTS), peripheral neuropathy, and CTS with peripheral neuropathy. DESIGN: Criterion standard. Mixed median NCV studies across the forearm were added to routine CTS investigational protocols. SETTING: University outpatient setting, rural referral base. PARTICIPANTS: Thirty healthy volunteers and 60 patients referred with symptoms and signs suggestive of CTS and/or peripheral neuropathy. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Motor sensory and mixed median nerve conduction velocity across the forearm. RESULTS: The mean mixed median NCV across the forearm was 64.5 m/s in healthy subjects and subjects with CTS. The mean mixed NCV in subjects with peripheral neuropathy was 54 m/s, even in the presence of CTS. CONCLUSION: Mixed median NCV in the forearm added to the standard protocols is helpful in differentiating the diagnosis of CTS from peripheral neuropathy and CTS with peripheral neuropathy.

Adult↗

PubMed2002

Early assessment of post-stroke patients entering acute inpatient rehabilitation: utility of the WASI and HVLT-R.

OBJECTIVE: To examine the clinical utility of two brief assessment tools, the Wechsler Abbreviated Scale of Intelligence (WASI) and the Hopkins Verbal Learning Test-Revised (HVLT-R). We hypothesized that these measures would predict continued need for supervision and functional outcome at discharge. DESIGN: In this retrospective review, 44 patients with stroke who were admitted for acute inpatient rehabilitation were measured on five variables: WASI, HVLT-R, length of stay, FIM discharge scores, and need for supervision on discharge. RESULTS: Performance on the HVLT-R and WASI matrix reasoning subtest of the WASI was predictive of cognitive discharge scores on the FIM and need for supervision on discharge. The WASI similarities subtest was not associated with outcome. CONCLUSIONS: WASI matrix reasoning and HVLT-R are brief neuropsychological measures that are predictive of need for supervision and functional outcome in the acute stroke rehabilitation setting.

Aged↗